code: def test_steiner_tree(self):
      valid_steiner_trees = [
          [
              [
                  (1, 2, {"weight": 10}),
                  (2, 3, {"weight": 10}),
                  (2, 7, {"weight": 1}),
                  (3, 4, {"weight": 10}),
                  (5, 7, {"weight": 1}),
              ],
              [
                  (1, 2, {"weight": 10}),
                  (2, 7, {"weight": 1}),
                  (3, 4, {"weight": 10}),
                  (4, 5, {"weight": 10}),
                  (5, 7, {"weight": 1}),
              ],
              [
                  (1, 2, {"weight": 10}),
                  (2, 3, {"weight": 10}),
                  (2, 7, {"weight": 1}),
                  (4, 5, {"weight": 10}),
                  (5, 7, {"weight": 1}),
              ],
          ],
          [
              [
                  (0, 5, {"weight": 6}),
                  (1, 2, {"weight": 2}),
                  (1, 5, {"weight": 3}),
                  (3, 5, {"weight": 5}),
              ],
              [
                  (0, 5, {"weight": 6}),
                  (4, 2, {"weight": 4}),
                  (4, 5, {"weight": 1}),
                  (3, 5, {"weight": 5}),
              ],
          ],
          [
              [
                  (1, 10, {"weight": 2}),
                  (3, 10, {"weight": 2}),
                  (3, 11, {"weight": 1}),
                  (5, 12, {"weight": 1}),
                  (6, 13, {"weight": 1}),
                  (8, 9, {"weight": 2}),
                  (9, 14, {"weight": 1}),
                  (10, 14, {"weight": 1}),
                  (11, 12, {"weight": 1}),
                  (12, 15, {"weight": 1}),
                  (13, 15, {"weight": 1}),
              ]
          ],
      ]
      for method in self.methods:
          for G, term_nodes, valid_trees in zip(
              [self.G1, self.G2, self.G3],
              [
                  self.G1_term_nodes,
                  self.G2_term_nodes,
                  self.G3_term_nodes,
              ],
              valid_steiner_trees,
          ):
              S = steiner_tree(G, term_nodes, method=method)
              assert any(
                  edges_equal(list(S.edges(data=True)), valid_tree)
                  for valid_tree in valid_trees
              )
  
file_path: networkx/networkx/algorithms/approximation/tests/test_steinertree.py
imports: import pytest
  import networkx
  from networkx.algorithms.approximation.steinertree import metric_closure, steiner_tree
  from networkx.utils import edges_equal
label_desc: Use image node_id 4 for calling the TestSteinerTree obj's underlying member method code with example usage: obj.test_steiner_tree() without return types